This invention relates to polishing machines generally and more particularly to portable motorized polishers suitable for polishing automobiles as well as for a great variety of household and industrial uses.
In the past portable polishing devices have been manufactured in various designs. Essentially each of these has had an electric motor mounted in a housing and having a polishing wheel attached to the lower end of the electric motor drive shaft. A few examples of this type of structure are illustrated in U.S. Pat. Nos. 2,379,997, 2,443,023, and 3,084,364. In each of these polishing devices a handle for holding or gripping the device has been mounted to extend laterally outwardly from only one side of the electric motor housing. This type of gripping handle has not been convenient for applying greater pressure to the polishing wheel on the surface being polished. There is a tendency with this type of a handle or grip for the polishing device to try to squirt out from under the control of the user. Also the polishing wheel of the polishing devices referred to above in the United States Patents, only rotate about the shaft of the electric motor and this can cause distinct spots to be formed on the surface being polished.
Some other prior art portable polishing devices are illustrated in U.S. Pat. Nos. 2,014,119, and 2,542,158. These polishing devices have been designed with the handle located above the device so that varying degrees of pressure can be applied to the polishing wheel while it is being applied to the surface to be polished. The location of the gripping handle above the device has necessitated the use of suitable gearing on the electric motor shaft to drive a second shaft oriented 90.degree. to the electric motor shaft. Both of the polishing devices illustrated in these patents only have the polishing wheel rotating about a driven shaft perpendicular thereto.
It is an object of the invention to provide a portable polishing device primarily adapted to eliminate the great amount of motion performed by the arm of the person polishing an automobile by means of a cloth held in the hand, and thus eliminate the consequent fatigue.
It is also an object of the invention to provide a portable polishing device of simple design and having few parts.
It is also an object of the invention to provide a portable polishing device that may be manufactured economically and is highly efficient in operation.
It is a further object of the invention to provide a portable polishing device whose center of gravity is so located that the polishing device will automatically right itself anytime a tipping force is removed.
It is a further object of the invention to provide a polishing device that can be easily tipped or tilted to follow a curved contour surface that needs to be polished.
It is a further object of the invention to provide a portable polishing device having handle grip structure that can be gripped simultaneously on opposite sides of the polishing device.
It is an additional object of the invention to provide a portable polishing device having an eccentric orbital polishing motion.
It is an additional object of the invention to provide a portable polishing device whose handle gripping structure facilitates the application of greater pressure on the polishing device against the surface being polished.